From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Noise complaint in the servo drive, comparing a 7 to 1 reduction with a 10 to 1 reduction.
| Identifier | ExFiles\Box 182\M20\M20.1\ img053 | |
| Date | 27th June 1924 | |
| TO HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} S E C R E T. R5/M27.6.24. Copy to CJ. BJ. " WOR.{Arthur Wormald - General Works Manager} RG.{Mr Rowledge} " E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} " BY.{R.W. Bailey - Chief Engineer} EF. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. SERVO DRIVE. X9910 You complain of noise in the servo drive which is confined to the 7 to 1 reduction, and is alright in the 10 to 1. My limited experience was that this matter did not appear serious as the noise only occurred at certain speeds, and only when applying the brakes. Apparently the noise occurs frequently enough for it to be objectionable. My own impression is that the cause of the noise is due to some unsteadiness in the driving shaft as regards torsional speed. If changing the relative speed of the primary and secondary shaft of the servo drive is not effective I shall consider this proved. I can hardly believe that you will be able to detect the difference between the 7 to 1 and the 10 to 1 drive in practice. One thinks that with the 10 to 1 drive the user would be forced to adjust his brakes closer or more frequently, but I do not know that this is serious, so I should like you to reconsider whether the 10 to 1 drive (which has the extra advantage of the servo remaining longer in correct adjustment) could not be adopted as standard. Personally I think it could. I shall be glad to hear your views when you have had time to again go over the tests. R.{Sir Henry Royce} | ||